Inhibition of color formation during sulfation



wash-Mn.

United States Patent INHIBITION OF COLOR FORMATION DURIN SULFATIONRobert C. Harrington, Jr., Kingsport, Tenn., as'signor to Eastman KodakCompany, Rochester, N.Y., a corporation of New Jersey No Drawing.Application May 23, 1956 Serial N0. 586,652

7 Claims. (Cl. 260-458) This invention relates to the synthesis of lightcolored sulfated products. More particularly it relates to an improvedprocess wherein certain compounds may be added to the reaction forproducing-sulfated fatty alcohols for inhibiting the formation ofundesired color during the carrying out of said reactions.

Sulfation or sulfamation or the like treatment of various organiccompounds is a well-known procedure in industry. Many procedures andmaterials for carrying out such type of process are described in theprior art, such as in the publication Unit Processes in OrganicSynthesis, by Groggins. Also, the publication Industrial and EngineeringChemistry, for September 1954, describes a number of processes forsulfating various: compounds.

In general in the prior art the sulfating agents used are sulfuric acid,chlorosulfonic acid and sulfamic acid. While such prior art sulfatingmedia and processes have been economical and successful for manypurposes, there has resulted in many instances a darkening of thedesired product.

Previous approaches to preparing light colored products have frequentlydealt with the use of bleaching agents on the sulfated product after thecompletion of the reaction. Other methods of improving thequality of thesulfated alcohol have been concerned with the use of involved or costlymethods of sulfation which require elaborate equipment, unusualconditions or call for the handling of hazardous chemicals such asliquid sulfur trioxide.

There are a number of instances in the industry whereit is desirable tohave a light colored product. For ex-' ample, in the treatment oftextiles where sulfated com-. pounds are frequently used, it is apparentthat the employment of such sulfated compounds which do not have. a goodcolor may tend to detract from the quality of the treated textile. It isapparent, therefore, that providing an improved process whereby sulfatedproducts of improved color may be obtained, represents a highlydesirable result. i

This invention has for an object to provide an im-'.; proved process forpreparing light colored sulfated products such as light colored sulfatedfatty alcohols; Still another object is to provide a relativelyeconomical and simple method for sulfating fatty alcohols in high yieldsand of light color. An additional object is to provide an improvedmethod as indicated which will produce light colored sulfated fattyalcohols which may be used for surfactants, detergents, yarn treatingagents and the like purposes. A still further object is to provide animproved method for pro'dueinglight colored productsof the classindicated, which method may be carried out in highly colored products.

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product. A still further object of this invention is to provide aprocess which will produce light colored ammonium salts of sulfatedfatty alcohols. Still another object of this invention is to provide aspecies of process which permits the production of light coloredproducts and which may be applied to unsaturated long chain alcohols.Other objects will appear hereinafter.

After extensive investigation I have found that there are certainchemical compounds which I term color inhibitors which chemicalcompounds may be incorporated in sulfation reactions to greatly reducethe amount of color formed in these reactions. Sulfated productsprepared by the method of this invention are generally uniformly lightin color and retain their whiteness inthe acidic state over long periodsof standing or even under the influence of moderately high temperatures.This is believed to be an unexpected result as it is well-. known thatsulfated alcohols in the acidic state tend to decompose on standing. Or,such sulfated alcohols on being warmed for a short period of time tendto give While my invention in its broader aspects may be described asincorporating color inhibitors into sulfation reactions, for a betterunderstanding of the details of my invention, I will consider myinvention under the following three headings:

A. In accordance with this phase of my invention a thioamide type ofcompound would be added to the sulfation reaction as a color inhibitor.Examples of the compounds which have been found to be effective are asfollows: thiourea, 1,3-diethyl thiourea, 1,3-dirnethyl thiourea, l-allylthiourea, and thioacetamide.

. mechanism concerning the color inhibitor reaction is not known, it hasbeen found that compounds of the thioamide type referred to above,namely compounds which contain a sulfur atom, and which can exist in thetautomeric form as shown below are effective color inhibitors.

in sulfation reactions of the type under consideration:

i r CNH2.:',C=NH Therefore, under this phase of my invention a thioamide type of compound as illustrated above is incorpoconventionalequipment an'd with easily obtained ingredi- I to remove from orundesirable to leave in the finished rated in the sulfation reaction.That is, the alcohol to be sulfated has mixed therewith, for example, asmall, amount'of the thio compound. Thereafter the sulfating agentsuchas sulfuric acid is added with agitation. By this procedure whereincolor inhibitor is present, the. initial formation of color bodies isbypassed and a much purer final product is made possible.

B. In accordance with this phase of my invention I have found species ofprocess particularly adaptable to preparing ammonium salts of sulfatedalcohols characterized by being light in color and having good stabilityunder conditions of high temperature or long standing. Aparticularlynoteworthy aspect of this part of my invention is theapplication of my process to the sulfama tion of unsaturated alcohols.As far as I am aware, nowhere has the use of thio compounds of the classindicated been described as color inhibitors in the processing ofunsaturated alcohols. In'accordance with this part of my invention, forexample, the sulfated fatty al-' cohols are prepared much the same as inthe usual manner using various known catalysts such as acetamide or ureaand in addition incorporating into the reaction a color inhibitor inaccordance ith the present invention.-

Sul fation reactions under this part of my invention appatently dependon the presence of a catalyst such as acetamide to drive the sulfamationto completion, while the thioamide addition in accordance with thepresent invention serves only to reduce the amount of color formed andapparently has little catalytic eifect on the sulfamation reactionitself. It is thought important to discuss this point in order thattechnical differences of the process in accordance with the presentinvention may be observed over the prior art.

This fact that in the present process my thioamide addition functions asa color inhibitor and not as a catalyst is amply supported byexperiments which show that sulfamation of oleyl alcohol in the presenceof a thioarnide of the present invention, by itself results in. littleor no reaction even over extends periods of heating to relatively hightemperatures, say above 120 C. The mixture resulting from this treatmentin the presence of the thioamide and without a catalyst, is ofrelatively dark color and shows negligible sulfation activity.

On the other hand, if the same type of reaction is carried out usingboth a catalyst such as acetamide and a color inhibitor in accordancewith the present invention, such as thiourea, the resultant product isuniformly light in color, has a high organically combined 80;; value andshows good surface activity. Here again the exact manner in which thethioamide compound of the present invention functions to reduce theamount of color is not known. However, it appears that compounds capableof existing in the tautomeric form shown below are effective in thisfeature of reducing color. Thiourea is one of the simplest compounds ofthis type. The general class of compounds may be formulated as follows:

where R can be an H, alkyl (CH CH (CH or I have further found inreactions of this type that thiourea and its derivatives are quitecompatible in the reaction mixtures. Due to the fact, as mentionedabove, that a sulfarnation catalyst is present, the thiourea need onlyserve to effect the reaction in such a manner that the final color ismuch lower than when no color inhibitor is used. The general reactionunder this part of my invention for making ammonium salts of sulfatedfatty alcohols, may be illustrated by formula as follows:

HzNSOaOH and ROH----- ROSO1ONH4 thiourea 120 0. alkyl ammonium sulfateIn the above formula R represents a saturated or unsaturated aliphaticchain of 5-20 carbon atoms, and R represents an aliphatic fatty residueof 1-20 carbon atoms. While this part of my invention is particularlyapplicable to the treatment of unsaturated alcohols exemplified by oleylalcohol, my invention may also be applied to other unsaturated alcoholscontaining from 5-20 carbon atoms in a straight or branched chain. Alsomy invention may be applied to saturated alcohols containing from 520carbon atoms, examples of which are amyl, isoamyl, octyl, lauryl,octadecyl and the like. Also, certain other alcohols containing morethan one primary hydroxyl group or secondary hydroxyl group in additionto the primary hydroxyl group, exemplified by decanediol-l,10 andalcohols obtained by the hydrogenation of castor oil, may be treated.

Other alcohols which may be treated are as follows: aliphatic alcoholsin which the carbon chain is interrupted by other atoms or other groupssuch as --O--, --S--, -CO-, --CONH, --COO-, etc., examples of which arethe polyalkylene glycols, alkoxy ethanols, keto alcohols, acid-amidoalcohols, mono esters of glycols, etc.; and aromatic alcohols such asphenylethyl alcohol.

C. In accordance with the third part of my invention, 1 have found thatinhibition of color formation during spear-see; t

sulfation or sulfamation may be accomplished by incorporating thechemical compound hydrogen peroxide into the reaction. However, the useof hydrogen peroxide is somewhat more limited in that generally it wouldnot be used in a sulfation reaction wherein the sulfating media wasessentially comprised of chlorosulfonic or sulfamic acids. Expressed inanother way, I would prefer to use the hydrogen peroxide species of myinvention only when the sulfating media was comprised of sulfuric acid.The reaction under this part of my invention may be illustrated byformula as shown below:

A R OH-l-HzS 04+(HzOi)--- R OS OzOH (light colored) +H10 R=saturatedfatty residue A still further understanding of the details of myinvention will be had from a consideration of the several examples whichfollow. The first group of examples, namely Example I to Xvi, aredirected to operations in accord ance with part A of my invention. Thenext group of examples, XVII to XXI, will be for illustrating operationsunder part B. The remaining examples will be with regard to operationsunder part C. It is to be understood that these examples are set forthprimarily for illustrating certain specific embodiments.

EXAMPLE I Preparation of lauryl acid sulfate.0ne mole (186 grams) oflauryl alcohol was placed in a beaker, and to it was added 1 gram ofthiourea. Stirring was started, and at the same time, the addition of 1mole (98 grams) of concentrated sulfuric acid was begun. The sulfuricacid was added at such a rate that the temperature of the reactionmixture was maintained at 50 C. After all the sulfuric acid had beenadded, the temperature was raised to 70 C. for 15 minutes. On analysis,the resulting lauryl acid sulfate was found to have an organicallycombined value of 13.73%, and a color, on 50-50 dilution withisopropanol, of 81% transmittance at 400 mu.

EXAMPLE II Preparation of lauryl acid sulfate.-A total of 10 grams ofthiourea was added to 1 mole (186 grams) of lauryl.

alcohol in a beaker. Stirring was commenced and the addition of 1 mole(98 grams) of concentrated sulfuric acid started. The acid was added atsuch a rate that the reaction temperature was maintained at 50 C. At theend of this time, the temperature was raised to 70 C. for 15 minutesafter which a sample was analyzed to give the following results.Organically combined 50;, 15.61% and 81% transmittance (on 50-50dilution with isopropanol) at 400 mu.

EXAMPLE III Preparation of lauryl acid sulfate.--One mole (186 grams) oflauryl alcohol was placed in a beaker, and to it, with stirring, wasadded a sulfating mixture consisting of 5 grams of thiourea and 98 gramsof concentrated sulfuric acid. The sulfating mixture was added at a rateto maintain the reaction temperature at 50 C. At the end of this time,the temperature was raised to 70 C. for 15 minutes, after which a samplewas collected for analysis. The analysis showed this white sulfatedproduct to have an organically combined 80;, value of 14.76% and apercenttransmittance at 400 mu of 92.5%.

EXAMPLE IV EXAMPLE Preparation of lauryl acid sulfate-usingchlorasulfonic acid.-A sulfating mixture consisting of grams of thioureadissolved in 1 mole (116 grams) of chlorosulalong with the analyticalresults are tabulated as follows:

6. Oleyl alcohol was sulfated in 'a manner similar to the examples justlisted to show the applicability of these color inhibitors tounsaturated systems; The procedures,

Inhibitor Added Organit0.- Reaction cally 7 Example Color InhibitorSuliatlng Agent Temp., Color 1 Com- Number C. bined Alcohol SulfatlngS0,,

Agent Percent X 10 gramsthiourea Yes"... 0on0. Sulfuric.. 30 25 14 XIYes 30 18 12 XII -.do Yes".-. Ohlorosulfonicacid-- 20 10 13 XIII 10grams thioecetamide. Yes Cone. sulfuric 21 11 IV.. 10 grams 1-a1ly1-2-..do-... 60 13 thlourea. XV 10 grams 1,3-dlethyl-2- do 30 47.6 12' Vthiourea. XV Blan 25 0.0 I 11 1 Reported as percent transmittance at 500mu based on 50-50 dilution of sulfated product with isopropanol. Allreactions listed in this table were run using 1 mole (268 grams) oleylalcohol and 1 mole of sulfating agent.

fonic acid was added to 1 mole (186 grams) of lauryl alcohol at a rateto maintain the reaction temperature at -40 C. When the addition ofsulfating agent was complete, the reaction mixture was stirred for anadditional 30 minutes while a stream of air or nitrogen was blownthrough it to remove the hydrogen chloride. sample of the finishedmaterial had an analysis showing 16.4% organically combined S0 and acolor of 80% at 400 mu.

EXAMPLE VI EXAMPLE VII Preparation of lauryl acid sulfate usingthioacetamide as a color inhibitor.-Ten grams of thioacetamide was addedto 1 mole (186 grams) of lauryl alcohol, after which vigorous'stirring,and the addition of 1 mole (98 grams) of concentrated sulfuric acid wasstarted. The acid was added at a rate to maintain a reaction temperatureof 45 C. A sample of the white material obtained from this reactionshowed 46% transmittance at 400 mu (on 50-50 dilution with isopropanol)and an organically combined S0 content of 14%.

EXAMPLE VIII Preparation of lauryl acid sulfate using I-allyl-Z-thioureaas a color inhibitor.0ne mole of lauryl alcohol was sulfated atf50 C.with a mixture 'of 10 grams of 1"-allyl-2'-thiou'rea in 1 mole ofconcentrated sulfuricacid to give an exceptionally white product having"an organically combined SOQcontent of 14.98% and 91% transmittance at400 mu (after 50-50 dilution with isopropanol). p

' EXAMPLE IX Preparation of lauryl acid sulfateusing 1,3-diethyl-2-thiourea as a color inhibitor.0ne mole of lauryl alcohol was againsulfated at 50 C. with a mixture consisting of 10 grams ofl,3-diethyl-2-thiourea dissolved in one mole (98 grams) of concentratedsulfuric acid to give a white product. On analysis, this sulfatedmaterial showed an organically combined 50;, content of 16%, and 91%transmittance at 400 mu (on 50-50 dilution with isopropanol).

The following examples are set forth in particular for.

illustrating procedures in accordance with part B of the instantinvention: EXAMPLE XVII Preparation of oleyl ammonium sulfate usingsmall per-- centages of thiourea.A mixture of 268 g. (1 mole) of oleylalcohol, 1 g. of thiourea and 42 g. of mineral oil is placed in a beakerand stirred. The mixture is heated to 80 C. at which time 10 g. ofacetamide and 100 g. of sulfamic acid are added. The temperature is thenraised to 120 C. and held there for 50 minutes at which time the,

reaction is complete. The product was light in color and had a percenttransmittance at 500 mu (on 50-50.

dilution with isopropanol) of and anorganieally combined S0 value of19.6%. This product was highly surface active.

EXAMPLE XVIII Preparation of oleyl ammonium sulfate using intermediatepercentages of thiourea.A mixture of 268 g. (1 mole) of oleyl alcohol, 5g. of thiourea, and 42 g. mineral oil was placed in a beaker and heatedto C. with good agitation. At this point 10 g. of acetamide was addedalong with g. sulfamic acid. The temperature was next raised to C. for50 minutes to complete the reaction. A white, pasty product having apercent transmittance (on 50-50 dilution with isopropanol) at 500 muof83% was obtained. The organically combined S0 value was 21% and theproduct showed high surface activity.

EXAMPLE XIX Preparation of oleyl ammonium sulfate using high percentagesof thiourea.A mixture of 268 g. (1 mole) of oleyl alcohol, 42 g. ofmineral oil, and 10 g. of thiourea was heated to 80 C. with agitation.At this temperature 10 g. of acetamide and 100 g. of sulfamic acid wereadded and the temperature raised to 120 C. for 50 minutes. The productobtained at the end of this time was light in color having 84%transmittance at 500 mu (on 50-50 dilution with isopropanol). Theorganically combined 80;; value was 19.8%.

EXAMPLE XX Preparation of oleyl ammonium sulfate using I-allyl-2-thi0urea.A mixtureof 268 g. (1 mole) of oleyl alcohol, 42 g. ofmineral oil, and 5 g. of 1-allyl-2-thiourea This mixture was stirredandheated to 80 C. at which time 10 g. of acetamide and 100 g. of sulfamicacid were added. The temperature was then raised to 120 C. where itwas'maintained'fon 50 minutes. The product resulting from this reactionhad a. percent transmittance of 83.4% at 500 mu (on 50-50 dilution withisopropanol). The organically comwas placed in a beaker.

bined 80;, value was 18.26%.

EXAMPLE XXI Preparationof lauryl ammonium sulfate.-A mixture" of 186 g.(1. mole); of lauryl alcohol, 30 g. of mineral oil, and g; of thioureawere placed in a beaker and stirred; This mixture was heated to 80' C.at which time. 5 g. of acetamide and 100 g. of sulfamic acid were added;The reaction temperature was maintained at 120 C. for 50 minutes. Theresulting product was a white solid having 95.5% transmittance at 500'mu (on 50-50- dilution with isopropanol). This product alsohm anorganically combined S0 value of 21.5 and was highly surface active.

In the above Examples XVI-IXXI the sulfating com.- bination used, asclearly shown in these examples, comprised sulfamic acid in conjunctionwith a small amount of acetamide. For convenience of reference suchcombination is referred to hereinafter as suifamic acid-acetamidecatalyst.

Thatproceeding in accordance with my invention as described abovewherein the long chain alcohol to be treated has: added thereto a colorinhibitor chemical: with the beneficial. result-that an improved productis obtained, is further shown by the following tests. That is, under thefirst table which appears below, a sample of oleyl ammonium sulfateproduced in accordance with my invention is considered. It will be.noted from this table that the transmittance percent (quality of productbased on color). is very much better than product not pro duced inaccordance with my invention. That is, products produced by my inventionexhibit a relatively highvalue. of 84%., 83% or the like as comparedwith 47% for product not made, in accordance with my invention.

In the next table similar comparison is shown for lauryl ammoniumsulfate produced in accordance with my' invention, having atransmittance value of around 96% as compared with a lower value for aproduct produced in a conventional manner.

Table I OLEYL ALIMONIUM SULFATE l At 500 mu on 50-50 dilution withisopropanol. Organically combined S0 EXAMPLE XXII Preparation of laurylacid sulfate using dilute lauryl alcohol (high temperature).-A sulfatingmixture consisting of 98 grams of concentrated sulfuric acid and 2 gramsof 50% hydrogen peroxide was added slowly to a mixture consisting of 186grams. (1 mole) of lauryl alcohol and 20 grams of mineral oii. Thereaction temperaturercached 60 C. during the addition of the sulfatingmixture, and was thereafter maintained at 80 C. for minutes. A lightcolored product was obtained from this reaction which showed highsurface active properties.

EXAMPLE XXIII Preparation of lauryl acid sulfate using uming sulfuricacid-A sulfating mixture consisting of 98 grams of 15% fuming sulfuricacid and 2.5 grams of 50% hydrogen peroxide was added slowly, and withgood agitation, to a mixture consisting of 186 grams of lauryl alcoholand 20 gramsv of mineral oil. The temperature was allowed to reach amaximum of 45 C. during the addition of the sulfating mixture, but wasthen raised to. 60 C.. for 3.0 minutes, after which it was cooled toroom temperature. The resulting product was very light in color, had apercent transmission of 85% at 500 mu, and showed strong surface activeproperties.

EXAMPLE XXIV Preparation of lauryl acid sulphate (high peroxide content,high temperature).A sulfating mixture consisting of 98 grams ofconcentrated sulfuric acid and 5 grams of 50%. hydrogen peroxide wasadded to 186 grams of lauryl alcohol with good agitation. Thetemperature reached 55 C. during the addition, and was then raised to C,for 15 minutes, after which the product was cooled to room temperature.A white material was obtained. which showed 14% organically combinedsulfur trioxide and 100% transmission at 500 mu. Lauryl acid sulfateprepared by this method showed the usual surface active properties.

EXAMPLE XXVI Preparation of lauryl acid sulfate (intermediate peroxidecontent, high temperature) .-A sulfating'mixture consistof 98 grams ofconcentrated sulfuric acid and 3 grams of 50% hydrogen peroxide wasadded with good agitation to 136 grams of lauryl alcohol. Thetemperature of the reaction medium was kept at 70 C. for 15 minutesafter addition of the sulfating mixture and then cooled toroomtemperature. The: resulting product was a white. solid, had anorganically combined sulfur trioxide content of 14%, and a percenttransmission of 100% at 500 mu.

- EXAMPLE XXVIII Preparationof lauryl acid sulfate (low peroxidecontent; low z'empemture).-A sulfati'ngmixture consisting of 98 grams ofconcentrated sulfuric acid and 1 gram of 50% hydrogen peroxide was addedwith agitation to 1.86 grams of lauryl alcohol. The temperature of thereaction reached 50 C. during this addition, and was held at 50 C. foran additional 15 minutes. The cooled product was white in color andshowed transmis- The resulting product sion at 500 mu. The organicallycombined sulfur trioxide was 15% and the compound was highly surfaceactive.

EXAMPLE XXIX Preparation of lauryl acid sulfate (low peroxide content,high temperature).-A sulfating mixture consisting of 98 gramsconcentrated sulfuric acid and 1 gram of 50% hydrogen peroxide was addedwith strong agitation to 186 grams of lauryl alcohol. The temperaturereached 55 C. during this addition, but was raised to. 70 C. and

V held there for 15 minutes after the addition was'complete. The whiteproduct obtained from this reaction had an organically combined sulfurtrioxide content of 15% and a transmission of 99% at 500 mu.

In order to permit clearer understanding of the results obtained by thismethod of synthesis, the analytical values are listed in tabular form asfollows:

Examination of this table clearly shows the beneficial efiect that theinclusion of hydrogen peroxide in the sulfating mixture has. Usingreaction conditions consisting of a hydrogen peroxide content of 0.5gram to 2.5 grams per mole of concentrated sulfuric acid and atemperature range of 50-70" C., these variations still give a whiteproduct having a high organically combined sulfur trioxide content andgood stability on storage in the acidic state.

The particular and practical utility of my invention enabling theproduction of lighter'colored sulfated products is apparent to asubstantial extent merely from the visual inspection of the productsobtained. However, these benefits are further apparent whensulfated'alcohols are used in textile treating compositions. A textiletreating composition was made up containing 2% of light color sulfatedlauryl alcohol produced in accordance with the present invention. Thistreating composition was applied to continuous filament 150 deniercellulose acetate yarn. No darkening of the yarn was observed due tothis initial application. After a period of six months the yarn thustreated was examined. No darkening of the yarn was noted after thisextended period. The amount of the color inhibitor added by weight andwith respect to the weight of the alcohol being processed, would be fromthe relatively small amount of 0.1% to the higher amount such as 20%.

As may be seen from the above examples using the improved process of thepresent invention, in many instances the temperature of sulfation can bekept within the range above room temperature but below 100 C. Themaximum temperature which'would be employed generally will not exceed150 C. A suitable temperature range is from 50 to 130 C. The reactiontime in general, as indicated by the above examples, is only from V2hour to two hours. The maximum time of reaction "in general will notexceed about 4 hours. As indicated in the examples, I prefer tothoroughly agitate the sulfating media with the compound being sulfated.

I claim:

1. The process of sulfating long-chain alcohols to ob tain a product ofimproved color, which comprises incorporating with the alcohols 0.l20%,with respect to the weight of the alcohol, of a color inhibitor from thegroup consisting of thiourea, diethyl thiourea, dimethyl thiourea, allylthiourea and thioacetamide, agitating the aforesaid mixture,incorporating into the mixture 21. sulfat ing agent from the groupconsisting of sulfuric acid,

chlorosulfonic acid, and sulfamic acid-acetamide catalyst, holding thetemperature of the reaction within the range from room temperature to150 C., and after the reaction has taken place, isolating the sulfatedalcohol product of improved color.

2. The process in accordance with claim 1 wherein the long-chain alcoholis lauryl alcohol and the temperature is maintained between 50l30 C.

3. The process of preparing lauryl sulfate of improved color whichcomprises mixing lauryl alcohol with not more than 10% by weight ofthiourea as a color inhibitor, sulfating the aforementioned mixtureswith sulfuric acid while maintaining the temperature within the range of50-130 C.

4. The process of producing an oleyl sulfate exhibiting a transmittance(at 500 mu on 50-50 dilution with isopropanol) of greater than 58%,which comprises adding 0.l20%, with respect to the weight of thealcohol, of a compound from the group consisting of thiourea, diethylthiourea, dimethyl thiourea, allyl thiourea and thioacetamide as a colorinhibitor to the oleyl alcohol to be sulfated, then treating the mixtureof alcohol and color inhibitor with sulfuric acid while maintaining, thetemperature between 50-130 C.

5. The process in accordance with claim 4 wherein the sulfating agent ischlorosulfonic acid.

6. The process of sulfating an alcohol containing 10-20 carbon atomswhich comprises reacting the alcohol in the presence of 0.l20%, withrespect to the weight of the alcohol, of a color inhibitor from thegroup consisting of thiourea, diethyl thiourea, dimethyl thiourea, allylthiourea and thioacetamide incorporated with the alcohol, and in thepresence of a sulfating agent from the group consisting of sulfuricacid, chlorosulfonic acid and sulfamic acid-acetamide catalyst,maintaining the, temperature of the reaction between 50-130 C. andisolating the sulfated alcohol of improved color.

7. The process of producing a sulfate product of improved color from analcohol from the group consisting of lauryl alcohol and oleyl alcoholwhich comprises mixing the alcohol with 0. 1-20%, with respect to theweight of the alcohol, of a color inhibitor from the group consisting ofthiourea, diethyl thiourea, dimethyl thiourea,

allyl thiourea and thioacetamide, also incorporating a content ofmineral oil, agitating the aforesaid components and heating them toapproximately C. and then adding sulfamic acid and acetamide, raisingthe temperature to approximately C. and thereafter isolating reactionproducts of improved color.

References Cited in the file of this patent UNITED STATES PATENTS

1. THE PROCESS OF SULFATING LONG-CHAIN ALCOHOLS TO OBTAIN A PRODUCT OFIMPROVED COLOR, WHICH COMPRISES INCORPORATING WITH THE ALCOHOLS 0.1-20%,WITH RESPECT TO THE WEIGHT OF THE ALCOHOL, OF A COLOR INHIBITOR FROM THEGROUP CONSISTING OF THIOUREA, DIETHYL THIOUREA, DIMETHYL THIOREA, ALLYLTHIOUREA AND THIOACETAMIDE, AGITATING THE AFORESAID MIXTURE,INCORPORTING INTO THE MIXTURE A SULFATING AGENT FROM THE GROUPCONSISTING OF SULFURIC ACID, CHLOROSULFONIC ACID, AND SULFAMICACID-ACETAMIDE CATALYST, HOLDING THE TEMPERATURE OF THE REACTION WITHINTHE RANGE FROM ROOM TEMPERATURE TO 150*C., AND AFTER THE REACTION HASTAKEN PLACE, ISOLATING THE SULFATED ALCOHOL PRODUCT OF IMPROVED COLOR.